NASA's InSight "Hears" Their First Mars Meteoroid Impacts

 

Credits: NASA/JPL-Caltech/University of Arizona

Seismic waves from four space rocks that collided with Mars in 2020 and 2021 have been detected by NASA's InSight lander. These are not only the first impacts that the spacecraft's seismometer has detected since InSight touched down on the Red Planet in 2018, but also the first impacts that have produced seismic and acoustic waves that have been detected on Mars.

The impacts, which occurred between 53 and 180 miles (85 and 290 kilometers) from InSight's location in the Elysium Planitia region of Mars, are described in detail in a new paper that was published on Monday in Nature Geoscience.

The most dramatic entrance was made by the first of the four confirmed meteoroids, which are space rocks before they hit the ground: On September 5, 2021, it entered the atmosphere of Mars and exploded into at least three shards, each leaving a crater behind.

The Mars Reconnaissance Orbiter of NASA then flew over the presumed impact site to verify its location.Three darkened spots on the surface were seen by the orbiter through its Context Camera, which was in black and white.The orbiter's team then used the HiRISE camera to get a color close-up of the craters (the meteoroid could have left additional craters in the surface, but they would be too small to see in HiRISE's images) after finding these locations.

Brown University researcher and co-author Ingrid Daubar commented, "Those craters looked beautiful after three years of InSight waiting to detect an impact."

Credits: NASA/JPL-Caltech/University of Arizona

On May 27, 2020, scientists discovered that three additional impacts had occurred after reviewing previous data; Feb. 18, 2021;and 31 August 2021.

Why there haven't been any more meteoroid impacts on Mars has baffled scientists. The main asteroid belt of the solar system is right next to the Red Planet, so there are plenty of space rocks to leave scars on its surface. Since Mars' atmosphere is only one percent thicker than Earth's, more meteorites can pass through it without breaking up.

Over 1,300 marsquakes have been detected by InSight's seismometer. The instrument, which was provided by the French space agency Centre National d'Études Spatiales, is so sensitive that it can detect seismic waves from thousands of miles away. However, the impact that was identified as the cause of such waves for the first time was on Sept. 5, 2021.

The Science Behind the Strikes

Seismic data provide numerous clues that will assist researchers in gaining a deeper comprehension of the Red Planet. The majority of marshquakes are the result of heat and pressure cracking subsurface rocks. Scientists can study Mars' crust, mantle, and core by observing how seismic waves change as they travel through various materials.

The four meteoroid impacts that have been found thus far produced minor earthquakes of no more than 2.0 magnitude. While seismic signals from larger quakes, such as the magnitude 5 event that occurred in May 2022, can also reveal details about the planet's mantle and core, those smaller quakes only provide scientists with a glimpse into the Martian crust.

However, the effects will be crucial to modifying Mars' timeline. Raphael Garcia, lead author of the paper from the Institut Supérieur de l'Aéronautique et de l'Espace in Toulouse, France, stated, "Impacts are the clocks of the solar system. "In order to estimate the age of various surfaces, we require the current impact rate.

By counting the impact craters on a planet, scientists can approximate the planet's age:The older the surface, the more they see. Scientists can then estimate how many more impacts occurred earlier in the history of the solar system by calibrating their statistical models according to how frequently they see impacts occurring now.

A meteoroid's shock wave size and trajectory can be reconstructed using InSight's data and orbital images. When a meteoroid hits the ground, it explodes and sends a shock wave through the atmosphere .Sound waves travel through the air as a result of these events. This sound wave tilts the ground more when it reaches InSight the bigger the explosion. The lander's seismometer is sensitive enough to determine the magnitude and direction of a ground tilt caused by such an event.

Garcia stated, "We're learning more about the impact process itself." Now, we are able to correlate various sizes of craters with particular seismic and acoustic waves.

The lander has time to investigate Mars. The accumulation of dust on the solar panels of the lander is reducing their power and will eventually cause the spacecraft to shut down .It is difficult to accurately predict when, but engineers now believe that the lander could shut down between October of this year and January of 2023 based on the most recent power readings.